Throwaway-type cutting tools, including the case of using a negative-type cutting insert, are required to improve chip discharge performance.
Patent document 1 discloses a cutting insert with an inclined linear major cutting edge, and also discloses a cutting tool configured so that the major cutting edge has a positive axial rake when the cutting insert is attached to a holder.
However, this cutting tool has also failed to achieve sufficient chip discharge performance. Hence, there is a need to further improve chip discharge performance.